Conventional computing devices provide several input options for enabling a user to control such a computing device. For example, a user can use one or more physical keys of an alphanumeric keyboard communicatively connected to the computing device in order to control the computing device. Additionally, a user can use a movable cursor control device such as a mouse, a trackball, or a joystick communicatively connected to the computing device. Moreover, touch sensing technology can be used to provide an input option for user control of a computing device or other electronic device. The user may use the input device to indicate desired actions in menu navigation, cursor control, game play, and inputting a choice or a selection.
Within the broad category of touch sensing technology there exist capacitive sensing touchpad devices. Typically capacitive sensing touchpad devices are implemented with an input region in a flat or planar manner as shown in FIG. 1. FIG. 1 is a side sectional view of an exemplary conventional art design of a capacitive sensing touchpad 100 wherein a capacitive sensor 104 (which is well known in the art) can sense through a flat dielectric material 102. However, it can be desirable to produce a capacitive sensing touchpad device in the shape of a concave bowl, convex surface, or other non-flat shape. For example, the non-flat shape may be designed for industrial design reasons such as aesthetic appeal, or for functional reasons such as to ergonomically fit and to accompany the range of motion of a user's finger or thumb. One of the disadvantages of producing such a non-flat shaped capacitive sensing touchpad device is that it can result in non-uniform signal output due to non-uniform capacitive coupling, or be costly to design and fabricate.
The invention may address one or more of the above-identified issues.